Furnace.



' No. 723,802; 0 I PA'IBNTED MAR. 24, 1903. f A. w. STRAIGHT & G. B, STONE.

FURNACE.

APPLICATION FILED MAR. 1 1902.

H0 MODEL.

UNITED STATES ATENT OFFICE.

ASA WV. STRAIGHT AND GUSTIN B. STONE, OF CHICAGO, ILLINOIS.

FURNACE.

SPECIFICATION forming pafl of Letters Patent No. 723,802, dated March 24, 1903.

' Application filed March 1, 1902. Serial lilo. 96,261. (No model.)

1'0 ctZL whom, it may concern.

Be it known that We, ASA W. STRAIGHT and GUsTIN B. STONE, citizens of the United States, and. residents of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Furnaces, of which the followingis a specification.

This invention relates to furnaces, and relates particularly to muffle-furnaces especially designed and adapted for use by dentists in baking small porcelain articles, as artificial teeth and the like.

One object of the invention is to provide improved and simplified means for supporting the muflie of the furnace in order to secure an unobstructed spacearoundthemuffle, which will thus be exposed to the direct action of the heat on all sides and will insure the greatest efficiency and economy in said furnace.

A mufile-furnace of our invention consists of the various features, combinations of featnres, and details of construction hereinafter described and claimed.

In the accompanying drawings a mufflefurnace of our invention is fully illustrated.

Figure 1 is a sideview of a furnace of our invention. Figs. 2 and 3 are views of opposite ends of said furnace. Fig. at is a sectional view on the line 4 4 of Fig. 2. Fig. 5 is a sectional view thereof on the line 5 5 of Fig. 4, and Fig. 6 is a side view of the mufile.

Referring now to the drawings, 1 designates I the shell or casing of the furnace, usually made of iron or other suitable metal. One end of the shell or casing 1 is open and is adapted to be closed by a removable cap 2. The walls of the shell or casingl are protected by a lining 3, of suitable refractory material, said liningcomprisingaseparate cap-lining 4. Formed within the lining 3 is what may be termed the combustion-chamber 5 of the furnace.

Supported within the combustion-chamber 5 of the furnace is the muffle 6. As shown,

said muiile is shorter than said combustionchamber and is supported in the following manner: Formed around the open end of said muflie 6 is a flange 7, which projects outwardly and is adapted to be clamped between the adjacent faces of the sections 3 and 4 of the furnace-lining by securing the cap 2 in position, the relative lengths of the lining and easing being such that when the parts are assembled and the cap adjusted it will exert a strong endwise pressure on said lining. Preferably, also, a recess 8'is formed in the end of the section 3 of the furnace-lining adapted to receive the fiange7and to define its position relatively to the sides of said lining, so that there will. be an unobstructed space on all sides of said muffle. An extension 9 on the cap-lining 4 is adapted to enter the recess 8 to clamp the flange, and thus secure the muffle 6 in position.

Formed in the rear wall of the casing 1 and of the section 3 of the furnace-lining is an opening 10,through which heat, usuallyin the form of a blast from a gasolene-torch or the like, is supplied to said furnace, a depression 11 being formed in the lining of the furnace in line with said openinglO to permit access of the heat and flame to all parts of the combustion-chamber. Said shell or casing and furnace-lining are also provided with an opening 12, preferably in the top thereof, through which the products of combustion escape from said combustion-chamber.

The interior of the muffle 6 is accessible through an opening 13 in the cap 2 and the cap-lining 4.

As shown, the furnace is supported upon a rod 14, threaded into a boss 15 on the shell or casing 1, the lower end of which is fitted to an opening in a base 16 and is secured therein by means of a set-screw 17, thereby making provision for adjusting said furnace vertically.

We claim 1. In a furnace, the combination with a shell or casing, a cap, a lining comprising separate sections and a muffle, of a flange on said muifie which is adapted to be clamped between sections of said lining, substantially as described.

2. In a furnace, the combination with a shell or casing, a cap, a lining comprising separate sectionsand a muffle, of a flange on said muflie adapted to be clamped between sections 1 IOO shell or casing, a cap, a lining comprising separate sections and a lnufiie, of a flange on said muffle fitted to a recess in said lining and adapted to be clamped between sections of said lining, substantially as described.

4. In a furnace, the combination with a shell or casing, a cap, a lining comprising separate sections and a muflie, of a flange on said rnuflie adapted to enter a recess in one section of said lining and a projection on the opposite section of said lining adapted to enter said recess and clamp said flange therein, substantially as described.

In testimony that we claim the foregoing as our invention we affix our signatures, in pres- I5 ence of two subscribing witnesses, this 24th day of February, A. D. 1902.

ASA WV. STRAIGHT. GUSTIN B. STONE.

Witnesses:

W. J. DE LABY, JOHN A. McKEoWN. 

